It had been nearly a year since you won that labor lottery. This job had quickly turned into the best thing that has ever happened to you and your family. From the Grestin checkpoint, you had seen it all; terrorist attacks, long-seperated lovers getting back together, people trying to smuggle drugs into the country...
None of that compares to the day a portal opens to an alternate dimension just outside the walls.
Which is bad, because inevitably that means more papers for you to check and double check.
But still, a job's a job. Might as well keep a straight face about it...
And remember:
Glory to Arstotzka.

The Shaper is a smith of unparalleled skill, her creations the most sought after in the fallen world. When a pony named Lyra comes to her with a unique commission she has to put all her skill to the test to craft a weapon of great power. For Lyra's goal is not an easy one, and it is not just any weapon that can kill a Dragon.

A story inspired by this and this image, as well as this challenge by CDRW (whose fic A Still More Glorious Dawn Awaits is quite good).

This story is a sequel to Stardust

When Equestria’s newest member of royalty asks for aid to be offered to her friends from abroad, the best and the brightest volunteer to serve. Captain Steel Song of the Dusk Guard are immediately mobilized to help XCOM defend their world from the enemies that besiege them. However, their first joint operation with the humans takes a turn for the worse and they quickly find themselves fighting for their lives against the full force of the monsters that threaten Earth.

(Stardust/Dusk Guard crossover)
(Coverart provided by a friend of Viking ZX!)
(While familiarity with both stories isn’t required, it is recommended)
(Many thanks to Arzoo for pre-reading!)
(All screenshots can be found at XCOM.wikia.com)
(Featured on 3/13/2013. Thanks everyone!)
(Now has it's own section on TVTropes as part of the Stardust series!)

Once a year, the Night Guards of Canterlot receive a very important shipment, much to the distress of their peers. Flash Sentry has no idea what the fuss is all about.

(Submission for EqD's Friend Off event.)

Everypony has a story. Some tell of heroic feats and grand adventure. Others tell of villainy against the forces of Harmony. The story of an average guard, however, is one of obscurity. They live in the background, unnoticed but ever-present.

Silent Knight assumed his tale would be like that of his father's: join the Royal Guard and serve Equestria. He would be just another helmet and spear, part of the rank and file. And that was all he ever wanted.

However, when Captain Shining Armor asked for volunteers to form a House Guard for the recently returned Princess Luna, it was Silent's hooves that stepped forwards to set his new life in motion.

Just another glorious day in Ponyville, till the nanite infection is activated. Now it's up to Rarity and an infected Twilight to save the world. This will prove easier said than done though as old friends, enemies, and teachers come out of the wood work, and they all want to shut down the intrepid pair. But have n/ ...detgruhfihvdsivbhdsfh
.
..
...
Insubordinate data terminated. Run Program: Imperium.

Credit for the cover pic goes to Thattagen of here and Deviant art. Be sure to like, fave, and follow.

A flip of a coin. A twist of fate.

Twilight Sparkle, younger sister of Princess Celestia's personal student, Shining Armor, grew up listening to her brother's bygone dreams of joining the elite of the elite: The Royal Guard.

Now, fresh out of the Academy, this young mare is ready to prove herself equal to the deeds of the great soldiers she read about as a filly. Too bad the princess she ends up protecting isn't Celestia.

Derpy Hooves is secretly a changeling.

Nopony particularly notices, or cares.

(New 9/15/19: Spanish translation by Spaniard Kiwi! Thank you!)

"Dear Princess Celestia, as your (former) most faithful student, I feel I have to warn you that this is probably a trap. Chrysalis cannot possibly be serious about this. Why would anyone, much less her, want to shoot a documentary on us?"

Chrysalis, queen of all the changeling hives and infinitely cunning architect of their plans to conquer Equestria, has a problem: She knows diddly-squat about ponies. But Chrysalis is cleverer than most—or all—changelings, and she's already devised a brilliant solution to this trifling issue: Make a movie about them.

Tenth place winner in Equestria Daily's Outside Insight contest.

This story is a sequel to A Stitch in Time

Having discovered the message left for her by Star Swirl the Bearded in the distant past, Twilight once again finds herself caught up in the middle of a struggle against forces far greater than herself. In order to even stand a chance she'll need to travel further and wider than she ever has, and forge some unlikely alliances with old enemies. All to bring down the powers that have manipulated and shaped her entire life, and retake control of her own future.

The conclusion of the Time Loop Trilogy, which began with Hard Reset
Available in Spanish thanks to dgs1993
Series TV Tropes page